Ok I run 37 total and 17 initial on my 452 headed 451 with 10.2.1 CR. Car starts with no kick back and after 12 years of running this thing with a 110 octane/pump 91 mix it is where it runs best. Enter last year and I added a FAST EZ efi with the O2 sensor and figure no more leaded race gas and I get ping now lugging it and when rolling into the throttle at anything below 2500 rpm and its all good above 3000 rpm. Running MSD Billet dizzy and MSD Digital 6 box. Been thinking about heavier springs in the dizzy but am afraid im gonna lose the throttle response. Im just frustrated with the quality of fuels these days at the pump, its all pretty crap.